Gas-blast circuit breaker



Oct. 21, 1941. H. MILLIKEN GAS-BLAST CIRCUIT BREAKER Filed March 27, 1940 4 Sheets-Sheet 1 mm kw \HVENTO R H. M ILL! K EN ATTORNE S Oct. 21, 1941. H. MILLIKEN 2,260,138

GAS'BLAST CIRCUIT BREAKER Filed Marc 27, 1940 4 Sheets-Sheet 2 INVENTO R 2 7 I-LMILLIKEN ATTOR N Y5 H. MILLIKEN GAS-BLAST CIRCUIT BREAKER Oct. 21, 1941.

4 Sheets-Sheet 4 Filed March 27, 1940 mvswroxq ELMILLIKEN ATTOR m jw.

- i was st. 21, 1941 @ITED STATES PATEN'l' OFFICE GAS-BLAST ontom'r BREAKER Humphreys Millikan, Mount Royal, Quebec,

Canada Application March 2'3, 1940, Serial No. 326,257

. 14 Claims.

This invention to gas-blast circuit breakers for electric pot. lighting systems. More particularly, the i entionconsists in lin movements the design and relative arrange- ;ie component parts of such circuit .Jcl in the provision of improved means :tor ope mng same.

021a object of the invention is to provide a general rte-proved circuit breaker-of the gas blast so deal ed and relatively arranged as to effect a suosts reduction in the overall space occupied the breaker.

Another object is to provide a gas-blast circult hreaker in which the valve controliing the conduits through which gas blasts are delivered to the interrupter contacts is mechanically connected to the movable interrupter contacts so that the opening and closing of the latter is directly controlled by the opening and closing of said valve. Other objects of the invention will appear hereinafter.

In the drawings,

Fig. 1 is a plan view of the complete breaker. v

Fig. 2 is a. vertical sectional view taken sub circuit stantially along the line 2-4 of Fig. 1. In this view the component parts of the interrupter are shown in their open circuit position.

Fig. 3 is a view similar to Fig; 2 but showing the oomponent parts oi the interrupter in their closed circuit position. Y

Fig. 4 is a fragmentary vertical sectional view illustrating a slight modification.

Fig. 5 is a side elevation of a circuit breaker installed in an inverted pmition as compared with the circuit breaker shown in the preceding fi ures.

Fla. 6 is a rear elevation of the installation shown in Fig. 5.

In the present instance I have shown a 3- pole circuit breaker, each pole comprising an intemipter unit including a pair of stationary interrupter contacts I 8 and a cooperating movable interrupter contact H. The contacts ll and I! of each pole are located within an arc orifice ll provided within a suitable casing I9. Casing I9 is carried by an insulator II which, in turn, is secured to the upper end of a gas blast conduit 2|. The conduits 2| extend downwardly within a casing 22 and converge at their lower ends to form a valve seat 23 surrounding an orifice 2|- common to all of said conduits. A head 25 is e in. which the component parts are i it. Head '25 carries a diaphragm valve generally indicated at 23. Said valve comprises a rubber ring 27 having im outer marginal portion clamped or otherwise'tastened to the upper surporticn of the valve 25 is formed by a metal disc suitably secured to the inner periphery of the rubber ring 21. Disc 29 is provided with an upwardly extending sleeve portion 30 which telescopes the lower end of a tubular member 3! working in a tubular guide 32 formed integral with the blast conduits 2!. Incated within the sleeve 30 is a cylinder 33 having a top wall 36 provided with a central aperture 35 through which extends an axially movable rod 36 en ,the head 31 and' an inwardly directed flange ll provided at the lower end of member 3|. The casing head 25 is recessed to provide the bottom and side walls of a pressure chamber 43 the top wall of which is formed by the diaphragm valve iii Chamber I3 is provided with an inlet 44 and an outlet 45. Inlet ll is connected through pipe 46 and hand operated valve 41 to the main supply pipe 48 through which gas is supplied to the pressure chamber 50 abovevthe diaphragm valve 18. Pipe 48 is equipped with a hand valve BI and a non-return valve 62. The gas supplied under pressure through pipe l8 may be drawn irom a storage tank or other suitable source.

The outlet 45 of chamber 43 is controlled by an I electrically operated valve 54. This valve is closed by the pressure or a spring and is momentarily opened by the energization of an operating coil l8.

Three contact operating arms 58 are rigidly fastened at their inner ends to the upper extremlty of the tubular member 3|. Each of the movable circuit breaker contacts [1 is rigidly fastened to the upper end of an insulating rod 59 having its lower end rigidly fastened to the outer extremity of one of the contact operating arms I58. It will be noted that the arms ll Vwork 111 slots on provided in the conduits 2|.

Each pole or phase or the circuit breaker is connected in series with a disconnecting switch generally indicated at 62. In the present inbolted to and forms the bottom wall or casing stance this is accomplished by connecting one 2 c-e of head 25 as indicated. at 28. The central a battery 08. The remaining terminal of coil is connected, through conductor 0! and crank arm II, to the movable arcuate contact 00 of switch 00. The stationary contact SI of switch 00 is-connected to the remaining terminal of battery =00 by closure of a manually operable switch 82 or by closure of an automatic relay contact 00, the latter being of a type which operates automatically in response to a fault in the system. Assuming that switches 02 or 93 are closed, it. will be seen that coil 08 is deenergized topermit closing'of the valve 54 by the spring '40 when the disconnecting switches 02 are moved to open-circuit position since, in this position of the disconnecting :switches, movable contact 00 of switch 00 is in the open-circuit position shown in Fig. 2. when the disconnecting switches are closed the contact 00 moves into engagement with contact 0|, thus closing switch 00. Relay contact 00 closes automatically in response to a fault in the system to energize coil 00 and thus open valve 04 to cause the circuit breaker to open. The operating coil 84 of valve II is connected across the battery 80 by closing switch 04 to close disconnecting switch 02.

In gas blast circuit breakers heretofore used 7 the contacts are operated by cylinders, pistons and linkages separate from the blast valve.

It is'evident that my invention eliminates such cylinders and pistons and simplifies the construction of the circuit breaker. The time of opening is also minimized by connecting the contacts mechanically to the diaphragm blast valve; furthermore there is no possibility of the interrupter contacts drifting open without the blast valve also opening and applying a blast of gas to extinguish the arcs.

Another novel feature of my invention is that the casing 22, blast conduits 2|, seat member and diaphragm valve 20 are relatively arranged so as to conjointly provide a compact blast valve assembly, the body of which is formed by the casing 22, the inlet to said bodybeing constituted by the supply pipe 48 and the outlet from said body being constituted by the orifice 24 which is common to the three blast conduits. I

A further advantage of the construction described herein is that it lends itself to a compact triangular arrangement of the three poles or phases of the circuitbreaker so that considerable space is saved as compared with conventional multi-pole circuit breakers in which the poles or phases are arranged in a row. In this connection, it will be noted that the interrupter units comprising the three poles or phases of the circuit breaker are arranged in triangular formation on top of the casing 22 so that they lie substantially within the area of the circle defined by the circumferential wall of the casing.

-The drawings show a circuit breaker having single movable interrupting contact in each pole but it is apparent that the same method or operation could be applied to Interrupters having several movable contacts in series for higher voltages, or the invention may be applied to interrupters having several movable contacts in multiple for carrying and interrupting higher currents.

As shown in Fig. 2, the contact operating arms I! carry movable banies "a which cooperate with stationary bames 00a to prevent excessive leakage of the blast through slots 00.

when the blast valve 20 is in open position, as shown in Fig. 2, the area of the movable valve member subjected to downward air pressure .is

substantially equal to the area subjected .0 upward pressure but the velocity of the upward blast through orifice 24 creates a counter-suction effect reducing the net pressure on the central portion of the movable valve member so that said member moves upward and closes the valve. This valve closing eflect of the suction created by the upward flow through orifice 24 has been. demonstrated by the fact that the valve fails to close when the blast velocity in conduits II is eliminated by closing off the outlets of said conduits. There is a structural advantage in this arrangement of equal areas.

It is desirable to close blast valve 28 as quickly as possible after the disconnecting switch has opened. Thisrequires a relatively large diameter'of inlet pipe 40 and its connection to space 43 but such a large inlet would cause slow opening of the blast valve which would be undesirable. In order to overcome these conflicting requirements an automatic throttle valve 990. may be provided as shown in Fig. 4. This valve comprises an upper cylinder IOI formed at its upper end to' provide a discharge nozzle I02 opening into pressure chamber 40 and having its lower .end connected to pipe 48 by connection I020. A

piston I04, working in cylinder III, is carried by the upper end of a piston rod I00. Piston rod I05 works loosely in a partition III which forms the upper wall, of a lower cylinder I01. A piston I08 is carried by the lower end of piston rod Ill and is normally urged downwardly by a spring I00 confined between said piston and the partition I08. The lower end of cylinder I01 is closed by a removable plug IIO. Piston I04, piston rod I05, piston I08, and spring I00 are normally positioned as indicated byfull lines in Fig. 4, with piston I44 closing cylinder I0! except for a slight leakage clearance between piston I04 and the wall of cylinder IOI which admits gas from pipe 40 into pressure chamber 43 at a rate sumcient to overcome leakage out of pressure chamber 40 and maintains pressure in 43. When valve 04 opens suddenly discharging gas from pressure chamber 43 to atmosphere, the unbalance of pressure above and below piston I04 causes this piston and the piston rod I00 to move upwardly; the inertia of these moving parts and the dashpot action of piston I00 serving to introduce a certain interval of time before piston I04 reaches nozzle I02 and this time interval is adjusted so that the diaphragm 21 reaches the bottom of its travel at the same instant piston I04 reaches the top of its travel; thus the inlet of gas to pressure chamber 43 is cut oil until it is required and then it is opened wide to reciose the movable diaphragm 27. After blast valve 04 closes, the pressure at both sides of piston I04 is ecual and said piston is moved downwardly to its closed position by the action of spring I00.

In Figs. 1 to 4 inclusive the circuit breaker is shown in an upright position but it will be understood that the circuit breaker may be installed and operated in a horizontal or a vertical position, or in any other desired position. or example, Figs. 5 and 6 show the invention embodied in a circuit breaker installed in an in tted posi-- tion as compared with the circuit in are shown in the preceding figures. In E and 6 the three conduits ii are arranged in a line instead of being arranged in triangular formation and are inverted so that the valve seat 23 faces upwardly instead of downwardly. In Figs. 0 and 6 the disconnecting switches 42 and their operating connections, including the piston II and the what I claim is:

1. A gas-blast circuit breaker comprising stationary and movable interrupting contacts, a source of gas under pressure, a conduit through which a blast 0! gas is delivered from said source to said contacts. a valve controlling communica= tion between said source and said conduit, means connecting said valve to at least one of the in terrupting contacts whereby said contacts are moved to the open-circuit position by'the open ing of said valve and to the closed-circuit position by the closing of said valve, said means permitting the valve to have a limited movement independently of the connected interrupting contact whereby the valve may be opened to a certain extent prior'to the movement of the interrupting contacts. to open-circuit position.

2. A circuit'breaher as set forth in claim 1 in which the said means also serves to hold the interrupting contacts against drifting to opencircuit position as long as the valve is in its closed position.

3. A gas-blast circuit breaker comprising a pair oi stationary contacts, a movable contact cooperating with said stationary contacts. a source of gas under prenure, a conduit through which a blast of gas is conveyed from said source to said contacts, a valve controlling communication between said source and said conduit and a lost motion connection between the valve and the movable interrup contact adapted to op crate the latter to open-circuit position in re sponse to movement of the valve to its open position.

4. A. gas-blast circuit breaker comprising a pair of stationary contacts, a movable contact cooperating with said stationary contacts, a source of gas under pressure, a conduit through which the blast oi gas is conveyed from said source to said contacts, a valve controlling corninunication between said source and said conduit;

and a resilient connection between the valve and a the movable interrupting ctect adapted to operate the latter to. open=circuit position in response to movement of the valve to its open position, said resilient connection permitting the valve to have a limited movement independently of the connected interrupting contact whereby the valve may be opened to a certain extent prior to movement of the interrupting contacts to open-circuit position.

5. A multi-pole circuit breaker comprising a plurality of interrupters each including amovable interrupting contact and one or more cooperating stationary contacts, a source of gas under pressure, a plurality of conduits, each serving to deliver a blast of gas from said source to one of saidinterrupters to extinguish the arcs drawn between the interrupting contacts when the movable contact is moved to open-circuit posi= tion, a single valve controlling communication between said source and all of said conduits and means affording a lost motion connection between said valve and the movable interrupter contact assures of each interrupter whereby theopening and closing of the contacts of each unit is controlled directly by the opening and closing movements of said valve.

6. a circuit breaker as set forth in claim'5 in which the source of gas under pressure comprises a tank into which the blast conduits extend, the valve controlling the delivery of the means for supplying gas under pressure to the chamber containing said valve seat, means for supplying gas under pressure tothe remaining chainlierto move said valve to a closed position against said seat and means for exhausting the gas from said last mentioned-chamber to shoot opening of said valve.

3. The combination with the construction set forth in claim 7 of a plurality of interrupters each including an arc orifice to which a blast of gas is delivered through one of said conduits and relatively movable interrupting contacts arranged in said orifice so that the are drawn between the interrupter contacts-when the latter are operated to open-circuit position is extinguished by the gas-blast delivered to the arc orifice in which said contacts are arranged.

9. A gas blast circuit breaker comprising a casing, a plurality of interrupters arranged above the top wall of thecasing in triangular forms tion, each interrupter including an arc orifice and interrupter contacts arranged in said orifice, a diaphragm valve dividing the interior of the casing into upper and lower non-communicating pressure chambers, air blast conduits extending downwardly through the top wall of said casing and having their inner ends joined together within the upper pressure chamber to form a downwardly facing valve seat defining a gasblast inlet coon to all of said conduits, the upper end of each blast conduit serving to support one of said interrupters and having its gas passage aligned with the arc orifice of said interrupter, means for supplying gas under pressure to said upper chamber for delivery through said conduits in the open position of said valve, means for supplying gas under pressure to the lower pressure chamber to close said valve against said seat and means for exhaustinggas from said lowerchainber to eiiect opening of said valve when it is desired to deliver a blast of gas through each of said conduits.

id. in a gas-blast circuit interrupter, a casing,- a diaphragm dividing the interior ofthe casing two pressure chambers of unequal size, a gas=hleet conduit extending into the larger of said chambers and having a. valve seat at its inner end, means for supplying compressed gas to both of said chambers from a common source, said smaller chamber being provided with an outlet through which compressed gas supplied to said chamber is relieved to atmosphere, 2. normally closed valve controlling the flow through said outlet and electro-magnetic means for opening said valve; said diaphragm being closed against said seat by the gas pressure in said smaller chamber when the valve controlling the outlet irom said smaller chamber is in its closed position, said diaphragm being moved away from said seat by gas pressure in the larger chamber when the pressure in the smaller chamber is reduced by the opening of the valve controlling the outlet from said smaller chamber, said circuit breaker being also characterized in that substantiallyequal areas of the diaphragm are exposed to the gas pressure established in said chambers when said diaphragm is in its open position away from said seat so that the velocity of the blast of air Whichis delivered from the larger chamber through the gas-blast conduit in the open position of the diaphragm serves to unbalance the forces acting against opposite sides of the diaphragm and to thereby assist in moving the diaphragm to a closed position against said seat.

11. A gas-blast circuit breaker comprising interrupter contacts, a source of gas under pressure, a conduit through which a blast of gas is delivered to extinguish the arcs drawn between the interrupter contacts when the latter are operated to open-circuit position, a valve controlling communication between said source and said conduit and movable mechanical connections between the valve and the interrupter contacts whereby said contacts are moved to open-circuit position by the valve when the latter is vmoved to open position to provide communication between the conduit and the source of gas under pressure.

12. A gas-blast circuit breaker as set forth in claim 11 in which the connections between the valve and the interrupter contacts serve to move said contacts to the closed-circuitpositionin respouse to closing movement of the valve.

13. A gas-blast circuit breaker comprising stationary and -movable interrupter contacts. a source of gas under pressure, a conduit through which ,a blast of gas is delivered from said source to said contacts, a movable valve member controlling communication between said conduit and said source, said valve member and at least one of the interrupter contacts being interconnected so that said interrupter contacts are moved to open-circuit position in response toopening motion of the valve and to closed-circuit position in response to closing movement of the valve,

said circuit breaker being further characterized in that the means interconnecting the valve and the interrupter contacts serves toretain the interrupter contacts in the closed-circuit position when said valve is in its closed position.

14. A gas-blast circuit breaker comprising interrupter contacts normally exposed to or surrounded by air at atmospheric pressure, a source of gas under pressure, a conduit through which a blast of gas is delivered to extinguish the arcs drawn between the interrupter contacts when the 

